Chint NJYB2
Control Relay
Rail-mounted three-phase three-wire voltage protection relay for 50 Hz circuits up to 415 V.
Product Overview
The Chint NJYB2 series voltage protection relay is designed for 50 Hz three-phase, three-wire control circuits with rated control supply voltages of 380 V, 400 V, or 415 V. Featuring a compact 36 mm wide rail-mounting housing, the series includes the NJYB2-G for phase loss and sequence protection, and the NJYB2-H for comprehensive monitoring including adjustable overvoltage, undervoltage, and phase unbalance. Contacts provide an AC-15 rating of 415 V at 0.47 A with a conventional thermal current of 3 A across operating temperatures from -25 deg C to +70 deg C.
Technical Parameters
| Rated Frequency | 50 Hz |
| System Phase/Wiring | Three-phase, three-wire |
| Contact Rating | Ue/Ie: AC-15 415 V/0.47 A; Ith: 3 A |
| NJYB2-G Contact Configuration | 1 changeover contact |
| NJYB2-H Contact Configuration | 1 changeover contact + 1 normally closed contact |
| NJYB2-H Overvoltage Protection | (1.05-1.3) x Us, adjustable; 0.1-10 s, adjustable |
| NJYB2-H Three-Phase Voltage Unbalance | (5%-15%) x Us, adjustable; 0.1-10 s, adjustable |
| Rated control coil voltage options | 380V, 400V, 415V |
| Mounting Type | Rail mounting |
| Ambient Operating Temperature | -25 deg C to +70 deg C |
| Electrical / Mechanical Life | 105 / 106 operations |
| Overall Dimensions (W x H x D) | 36 +/- 0.1 x 65.5 +/- 0.2 x 94 max mm |
| NJYB2-H Undervoltage Protection | (0.7-0.95) x Us, adjustable; 0.1-10 s, adjustable |
| NJYB2-G Protection Functions | Phase loss; phase sequence |
| NJYB2-H Protection Functions | Phase loss; phase sequence; overvoltage; undervoltage; three-phase voltage unbalance |
| Brand | Chint |
| Model | NJYB2 |
| Product type | Control Relay |
Key Selling Points
✓ Comprehensive protection coverage: NJYB2-G guards against phase loss and phase sequence, while NJYB2-H adds overvoltage, undervoltage, and three-phase voltage unbalance monitoring.
✓ Adjustable protection thresholds and tripping delays: NJYB2-H features overvoltage (1.05-1.3 x Us), undervoltage (0.7-0.95 x Us), and voltage unbalance (5%-15% x Us) with 0.1-10 s delay.
✓ Rated contact capacity: Contacts rated for AC-15 415 V at 0.47 A with an Ith conventional heating current of 3 A.
✓ Standard rail mounting profile: Compact dimensions of 36 mm width, 65.5 mm height, and 94 mm maximum depth enable efficient DIN rail integration.
✓ Robust operational endurance: Delivers an electrical life of 10^5 operations and mechanical life of 10^6 operations across ambient temperatures from -25 deg C to +70 deg C.
Technical Highlights
- Rated control supply voltage options: 380 V, 400 V, 415 V AC at 50 Hz (three-phase, three-wire).
- Output contact configurations: 1 changeover contact (NJYB2-G) or 1 changeover plus 1 normally closed contact (NJYB2-H).
- Adjustable delay timing: 0.1 s to 10 s trip delay for overvoltage, undervoltage, and unbalance faults on NJYB2-H.
- Contact ratings: AC-15 415 V / 0.47 A with Ith conventional heating current of 3 A.
- Endurance: 10^5 electrical operations and 10^6 mechanical operations.
- Operating ambient temperature range: -25 deg C to +70 deg C.
- Installation and dimensions: Rail mounting enclosure measuring 36 x 65.5 x 94 mm max.
Selection Guide
Select NJYB2-G for three-phase, three-wire applications requiring phase loss and phase sequence protection with 1 changeover contact. Select NJYB2-H when additional adjustable overvoltage, undervoltage, and three-phase voltage unbalance protection are required with 1 changeover and 1 normally closed contact configuration.
Reference Datasheet Pages
The following pages were selected from the model catalogue and are included for technical reference:
NJYB2 Catalog and Technical Data
